Pneumatically cooled enclosed finned heat sinks

ABSTRACT

A heat sink including one or more vented pipes for directing air through a plurality of enclosed chambers formed by a plurality of fins in an enclosed structure having at least a first side and a second side. An air inlet in the first side of the enclosed structure allows pressurized air to enter the plurality of enclosed chambers through the one or more vented pipes. An air outlet in the first side of the enclosed structure allows pressurized air to exit the plurality of enclosed chambers through the one or more vented pipes.

TRADEMARKS

IBM® is a registered trademark of International Business MachinesCorporation, Armonk, N.Y., U.S.A. Other names used herein may beregistered trademarks, trademarks or product names of InternationalBusiness Machines Corporation or other companies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to heat sinks for electronic devices, andmore particularly, to improved heat sink arrangements in enclosedhousings.

2. Description of Background

The use of heat sinks for electronic devices is well known. Typically, aheat sink is arranged proximate to a heat generating electroniccomponent such as a processor within a server. Heat generated byprocessor is transferred to the heat sink and then dissipated from theheat sink to the surrounding air. One type of heat sink includes ametallic base plate. Heat dissipating fins extend from the base plate toincrease the surface area of the heat sink. Heat transferred from thecomponent to the base plate is spread throughout the base plate and thefins.

As the operational speed and power density of a processor is increased,heat transfer from the processor to the surrounding environment becomesmore and more critical for maintaining proper operation of theprocessor. To further facilitate the dissipation of heat from theprocessor, a fan can be used to circulate air about outer surfaces ofthe fins and the base plate. However, in many system applications suchas computer servers, space is at a premium. A fan or other aircirculation device occupies space that may be needed for media access,cable ingress and egress, or performing periodic maintenance activities.Moreover, fans and air circulation devices generate noise which may beannoying or distracting in many system applications. Meeting theincreased heat transfer needs of more powerful processors adds to thechallenge of cooling new processor technology. What is needed is animproved heat sink design that is capable of moving a volume of airsufficient to cool processor and other heat sinks within a server orother electronic equipment. The improved heat sink design should notoccupy areas required for cable routing, media access, or maintenanceactivities, and should not generate undesired noise.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome and additional advantagesare provided in the form of a heat sink including one or more ventedpipes for directing air through a plurality of enclosed chambers formedby a plurality of fins in an enclosed structure having at least a firstside and a second side. An air inlet in the first side of the enclosedstructure allows pressurized air to enter the plurality of enclosedchambers through the one or more vented pipes. An air outlet in thefirst side of the enclosed structure allows pressurized air to exit theplurality of enclosed chambers through the one or more vented pipes.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with advantagesand features, refer to the description and to the drawings.

TECHNICAL EFFECTS

As a result of the summarized invention, technically we have achieved asolution wherein pressurized air is directed through a plurality ofvented pipes in an enclosed heat sink structure and across a pluralityof fins in the enclosed heat sink structure so as to dissipate thermalenergy, and so as to provide enhanced noise abatement relative tofan-cooled designs.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a perspective view of a pneumatically cooled enclosed finnedheat sink using vented pipes.

FIG. 2 is an isometric view of the pneumatically cooled enclosed heatsink of FIG. 1 with enclosure sides, top, and bottom removed.

FIG. 3 is a top view of the pneumatically cooled enclosed heat sink ofFIG. 1 with enclosure sides removed.

FIG. 4 is an exploded rear view of the pneumatically cooled enclosedheat sink of FIG. 1 with enclosure sides removed.

Like reference numerals are used to refer to like elements throughoutthe drawings. The detailed description explains the preferredembodiments of the invention, together with advantages and features, byway of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of a first example of a pneumaticallycooled enclosed finned heat sink using vented pipes. An enclosureincludes a first side 115, a second side 111, a third side 113, a fourthside 114, a top 112, and a bottom (not shown). An air inlet 116 formedby a vented inlet pipe 119 capable of accepting pressurized air entersthe enclosure on first side 115. An air outlet 117 formed by a ventedoutlet pipe 118 exits the enclosure on first side 115. Air outlet 117directs pressurized air from the enclosure to the ambient environment orto another enclosure (not shown).

FIG. 2 is an isometric view of the pneumatically cooled enclosed heatsink of FIG. 1 with enclosure sides 111, 113, 114, 115, top 112, andbottom removed. The enclosed heat sink includes a plurality of thermallyconductive fins 301, 302, 303, 304, 305. Pressurized air entering airinlet 116 exits one or more vent holes in vented inlet pipe 119,circulates in proximity to fins 301 and 302, and enters one or more ventholes of a first vented pipe 307 and a second vented pipe 321. Forexample, second vented pipe 321 includes a first vent hole 324 and asecond vent hole 325. In situations where noise abatement is to beprovided, at least two different size vent holes are provided in eachvented pipe to reduce acoustic resonance effects and noise resultingtherefrom. For example, a first vent hole 324 in second vented pipe 321is larger than a second vent hole 325 in second vented pipe 321, therebyproviding a measure of noise abatement. First vented pipe 307 isterminated at each end with an endcap 323, and second vented pipe 321 isalso terminated at each end with an endcap 323.

Air exits one or more vent holes in first vented pipe 307 and secondvented pipe 321, circulates in proximity to fins 302, 301, and 303, andenters one or more vent holes in a third vented pipe 311. Likewise, airexits one or more vent holes in third vented pipe 311, circulates inproximity to fins 303, 301, and 304, and enters one or more vent holesin a fourth vented pipe 309 and one or more holes in a fifth vented pipe319. Air then exits one or more vent holes in fourth vented pipe 309 andthe one or more vent holes in fifth vented pipe 319, circulates inproximity to fins 304, 301, 305 and enters one or more vent holes in asixth vented pipe 313. Air then exits one or more vent holes in sixthvented pipe 313, circulates in proximity to fins 305, and 301, andenters one or more vent holes in a seventh vented pipe 322. In theexample of FIG. 1, first, second, third, fourth, fifth and sixth ventedpipes 307, 321, 311, 309, 319, and 313 are shown as cylindrical pipeshaving circular cross sections for illustrative purposes. However, oneor more of these vented pipes could be fabricated from a plurality offlat members so as to provide vented pipes having polygonal crosssections as demonstrated by seventh vented pipe 322.

Air exits one or more vent holes in seventh vented pipe 322, circulatesin proximity to fins 301, 305, and enters one or more vent holes in aneighth vented pipe 312. Air exits one or more vent holes in eighthvented pipe 312, circulates in proximity to fins 305, 301, 304, andenters one or more vent holes in a ninth vented pipe 316. Air exits oneor more vent holes in ninth vented pipe 316, circulates in proximity tofins 304, 301, 303, and enters one or more vent holes in a tenth ventedpipe 310. Air exits one or more vent holes in tenth vented pipe 310,circulates in proximity to fins 303, 301, 302, and enters one or morevent holes in an eleventh vented pipe 306. Air exits one or more ventholes in eleventh vented pipe 306, circulates in proximity to fins 302,301, and enters one or more vent holes of a vented outlet pipe 118. Airthen exits from air outlet 117 of vented outlet pipe 118.

FIG. 3 is a top view of the pneumatically cooled enclosed heat sink ofFIGS. 1 and 2 with enclosure sides removed. With reference to FIG. 3, itmay be noted that fins 301, 302, 303, 304, and 305 form a plurality ofchambers interconnected by vented pipes. These chambers include a firstchamber 335, a second chamber 336, a third chamber 337, a fourth chamber338, a fifth chamber 339, a sixth chamber 334, a seventh chamber 333, aneighth chamber 332, a ninth chamber 331, and a tenth chamber 330.

Pressurized air enters first chamber 335 from vented inlet pipe 119. Airexits first chamber 335 from first and second vented pipes 307 and 321.Air enters second chamber 336 from first and second vented pipes 307 and321, and air exits second chamber 336 from third vented pipe 311 and atwelfth vented pipe 315 not visible in FIG. 2. Air enters third chamber337 (FIG. 3) from third and twelfth vented pipes 311 and 315, and airexits third chamber 337 from fourth vented pipe 309 and fifth ventedpipe 319. Air enters fourth chamber 338 from fourth and fifth ventedpipes 309 and 319, and air exits fourth chamber 338 from sixth ventedpipe 313 and a thirteenth vented pipe 317 not visible in FIG. 2.

Air enters fifth chamber 339 (FIG. 3) from sixth and thirteenth ventedpipes 313 and 317, and air exits fifth chamber 339 from seventh ventedpipe 322. Air enters sixth chamber 334 from seventh vented pipe 322, andair exits sixth chamber 334 from eighth vented pipe 312 and a fourteenthvented pipe 308 not visible in FIG. 2. Air enters seventh chamber 333from eighth and fourteenth vented pipes 312 and 308, and air exitsseventh chamber 333 from ninth vented pipe 316 and a fifteenth ventedpipe 318 not visible in FIG. 2. Air enters eighth chamber 332 (FIG. 3)from ninth and fifteenth vented pipes 316 and 318, and air exits eighthchamber 332 from tenth vented pipe 310 and a sixteenth vented pipe 314not visible in FIG. 2. Air enters ninth chamber 331 from tenth andsixteenth vented pipes 310 and 314, and air exits ninth chamber 331 fromeleventh vented pipe 306 and a seventeenth vented pipe 320 not visiblein FIG. 2. Air enters tenth chamber 330 from eleventh and seventeenthvented pipes 306 and 320, and air exits tenth chamber 330 from airoutlet 117 of vented outlet pipe 118.

FIG. 4 is an exploded rear view of the pneumatically cooled enclosedheat sink of FIG. 1 with enclosure sides removed. Fins 301, 302, 303,304, and 305 form a muffler-like structure that is air-cooled by meansof pressurized air applied to vented inlet pipe 119. The pressurized airflows through a plurality of chambers formed by fins 301, 302, 303, 304,305 by means of vent holes on vented pipes 307, 311, 309, 313, 322, 316,312, 308, 318, 310, 306 interconnecting these chambers. As air flowsthrough these vented pipes and chambers, the air absorbs thermal energyfrom fins 301, 302, 303, 304, 305. Air then exits from vented outletpipe 118.

The diagrams depicted herein present illustrative examples. There may bemany variations to these diagrams or the steps (or operations) describedtherein without departing from the spirit and scope of the invention.For instance, a different number of fins, vented pipes, and vent holesmay be provided other than what is shown in FIGS. 1-4. The terms “top”,“bottom”, and “sides” are relative and may be used interchangeably. Allof these variations are considered a part of the claimed invention.

While the preferred embodiment to the invention has been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

1. A heat sink including: an enclosed structure having at least a firstside and a second side; a plurality of fins in the enclosed structure; aplurality of enclosed chambers formed by the plurality of fins and theenclosed structure; one or more vented pipes for directing air throughthe plurality of enclosed chambers; an air inlet in the first side ofthe enclosed structure for allowing pressurized air to enter theplurality of enclosed chambers through the one or more vented pipes; andan air outlet in the first side of the enclosed structure for allowingpressurized air to exit the plurality of enclosed chambers through theone or more vented pipes.
 2. The heat sink of claim 1 wherein the one ormore vented pipes are vented by means of a plurality of holes.
 3. Theheat sink of claim 2 wherein the one or more vented pipes each include afirst hole having a first dimension and a second hole having a seconddimension, wherein the first dimension is larger than the seconddimension, thereby reducing or eliminating an acoustic resonance for theone or more vented pipes.
 4. The heat sink of claim 3 wherein the one ormore vented pipes are substantially cylindrical.
 5. The heat sink ofclaim 4 wherein the one or more vented pipes are capable of circulatingair in proximity to the plurality of fins such that the circulated airabsorbs thermal energy from the plurality of fins.